I've been wondering that, myself; looking at the 777 Production List, it's the only acft (apart from the very new ones) awaiting delivery.

I know Air Austral made a decision to reduce its route network. Perhaps this played a part; of course, another reason might be that the airline simply could not/cannot get sufficient financing for the aircraft .

A Google search brought up a news story in French datelined today May 15.

In summary, Google translate says that the story says that Air Austral are in financial dire straits which delayed the closure of obtaining the 73% of the financing required to be able to take delivery. But now a solution has been found (with the help of AF/KL group??) to allow them to be able to take delivery of the new 77L.

Don't know how reliable the source is. Just do a search for Air Austral Boeing. Perhaps native Francophones can tell us if my paraphrasing of the Google translation is accurate.

The best time to plant a tree is 40 years ago. The second best time is today.

UU is terminating its Sydney and Noumea services. If they are going to take delivery of the new B77L, then I would presume that the 2 B772ERs that are currently in the fleet are going to be disposed of. The airline is also operating 3 B77Ws and one more B77L.

Basically, on top of the SYD and NOU routes, all routes to French provincial airports will be terminated: NTE, BOD, TLS, LYS and MRS. Also BKK will be downgraded from B772 to B738 (fuel stop in MAA).

The only increase will be CDG, from 7x weekly to 12x weekly.

All that implies that the B77L, sitting at PAE isn't needed anymore and they are trying to sell it. No precision on the two B77E, whether they'll keep them or not. But with only one wide-body destination I'm not sure how they can keep 6 777's of 3 different types...
Finally, the article also implies that UU is trying to work out a solution with Airbus to defer deliveries of the two high-density A380s but they'd very much like to see their €30mil deposit back...

They state on their site that they're keeping 4 B777, 2 B737 and 3 ATR72. No indication on which 777 they want to offload. I guess they'll end up keeping 2 B77E and 2 B77W, however it sounds a lot to me, unless they plan on operating many charters. Or, unless they're operated à la TN like a pride tool to bring tourists in, whatever the cost.

I hope UU stays alive and ends up operating those A380. Now that's a good experiment there (good it will be as long as I won't find myself in one of those